[en] The importance of different sources of phenotypic variation, namely adaptation,
phenotypic plasticity, environmental maternal effects, ploidy level and genetic drift,
were estimated in several life history traits among populations of an invasive plant
species within its invasion range. Several common garden experiments were set out,
two of which in a reciprocal transplants experiment. The populations considered in
this study were located in Belgium, in France and in the native range of the model
species. Senecio inaequidens DC. (Asteraceae) is native to Africa. It was introduced
in Europe via wool trade in the late 19th century. In the native range, the species
occurs at two co-existing cytotypes: diploid and tetraploid. Only tetraploid individuals
are reported in Europe. The particular and well-documented invasion history of S.
inaequidens makes it an excellent plant model for evolutionary studies. Several life
history traits were measured, related to germination, growth and sexual reproduction.
The sources of phenotypic variation in those traits were analysed with respect to
climatic variation along altitudinal gradients in the invaded areas. The influence of the
ploidy level and the range (native vs introduced) on those traits was also analysed.
Results showed that diploid and tetraploid populations differed, mainly in winter
survival capacity. Along altitudinal gradients, clinal phenotypic differentiations with a
genetic basis were observed among populations. However, environmental maternal
effects were found to significantly influence phenotypic variation in areas with harsh
climatic conditions.
Monty A., Mahy G. 2009. Clinal differentiation during invasion: Senecio inaequidens
(Asteraceae) along altitudinal gradients in Europe. Oecologia 159:305–315.
Monty A., Lebeau J., Meerts P., Mahy G. 2009. An explicit test for the contribution of
environmental maternal effects to rapid clinal differentiation in an invasive plant. Journal
of Evolutionary Biology22: 917-936